"""author: zsw
   data: 2021/10/29
   project: aaaaaaa我爱学习
"""
# i=1
# while i>0:
#     pm = input("PM2.5为：")
#     if pm.isalpha():
#        break
#     else:
#         pm=float(pm)
#         if 0<=pm<=50:
#             print("空气质量为优")
#         elif pm>=51 and pm<=100:
#             print("空气质量为良")
#         elif pm>=101 and pm<=150:
#             print("空气质量为轻度污染")
#         elif pm>=151 and pm<=200:
#             print("空气质量为中度污染")
#         elif pm>=201 and pm<=300:
#             print("空气质量为重度污染")
#         elif pm>=300:
#             print("空气质量为严重污染")
#
# import random
# i=1
# gold=1000
# x=0
# while i>0:
#     u=input()
#     x=x+1
#     num1=random.randint(1,6)
#     num2 = random.randint(1, 6)
#     num3 = random.randint(1, 6)
#     titol=num1+num2+num3
#     if u=="exit" or gold<=100:
#         print("玩的次数：",x-1,"金豆：",gold)
#         break
#     elif 3 <= titol <= 10:
#         if u=="小":
#             gold=gold+100
#             print("玩的次数：", x, "金豆：", gold)
#         else:
#             gold=gold-100
#             print("玩的次数：", x, "金豆：", gold)
#     else:
#         if u=="大":
#             gold=gold+100
#             print("玩的次数：", x, "金豆：", gold)
#         else:
#             gold=gold-100
#             print("玩的次数：", x, "金豆：", gold)

str1=input()
y=len(str1)
y=int(y)
i=0
if y%3==1:
    for i in range(y):
        if i==0:
            # i=i+1
            print(str1[0]+","+"",end="")
        elif i==y-1:
            print(str1[i],end="")
        elif i%3==0:
            print(str1[i]+","+"",end="")
            # i = i + 1
        else:
            print(str1[i]+"",end="")
            # i = i + 1
elif y%3==2:
    for i in range(y):
        if i==y-1:
            print(str1[i],end="")
        elif i%3==1:
            print(str1[i]+","+"",end="")
            # i=i+1
        elif i%3==0:
            print(str1[i]+"",end="")
            # i = i + 1
        else:
            print(str1[i]+"",end="")
            # i = i + 1
else:
    for i in range(y):
        if i==y-1:
            print(str1[i],end="")
        elif i%3==2:
            print(str1[i]+","+"",end="")
            # i=i+1
        elif i%3==0:
            print(str1[i]+"",end="")
            # i = i + 1
        else:
            print(str1[i]+"",end="")
            # i = i + 1


# for i in range(1,10):
#     for j in range(1,i+1):
#         print(j,"*",i,"=",i*j,end="  ")
#     print()
